T3responsive is a project mainly written in JavaScript, it's free.
Responsive Web Design for TYPO3 4.5.x
h1. Make TYPO3 4.5.x work with responsive web design
In TYPO3 4.5.x all images generated with content elements (system extension css_styled_content) are renderd with fixed width and height in pixels. At the moment there's no possibility to get a flexible layout with percent including floating images. Ben van't Ende (TYPO3 Communty Manager) sent a "tweet":https://twitter.com/#!/benvantende/status/83896350214864896, that this is planed after the release of TYPO3 version 4.6.
You should know how responsive web design works and what are css media queries.
h2. How does it work
You have to do three steps to integrate this solution in your new responsive TYPO3:
h3. TypoScript
h3. CSS
h3. JavaScript
All image containers of images generated with the css_styled_content will get a percentaged width calcutated with help of their parent container. This calculation is only needed, if the window is smaller than your layout acually is designed for (default 980px).
h3. Useful fallback
If a client with a smaller resolution disabled javascript, this plugin won't work. So you can create different default widths for images in different situations. For examples please have a look in the css file %css_styled_content.css%. This fallback only works, if you use the css class no-js. Have a look in the html file index.html.
h2. Version
0.0.1 alpha - 2011-07-10 not ready for use and just for testing. Do not use on live websites! 0.0.2 alpha - 2011-07-19 integrate css and typoscript for css_styled_content but still alpha!